Displays controlled by flexible fins and droplets are more versatile and efficient than LED screens

Engineers at the University of Illinois at Urbana-Champaign have developed a new display that uses flexible fins, varying temperatures and droplets that can be arranged in different directions to create images. Controls are precise enough to enable complex movements, such as simulating a flower blooming. Image credit: Sameh Tawfick

Flexible displays that can change color, convey information and even send hidden messages via infrared radiation are now possible thanks to new research from the University of Illinois at Urbana-Champaign. Inspired by the deformation of the skin of animals such as chameleons and octopuses, engineers have developed capillary-controlled robotic flapping fins to create switchable optical and infrared light multipixel displays that are 1,000 times more energy efficient than light-emitting devices.

The new research, led by Sameh Tawfick, professor of mechanical science and engineering, shows how bendable fins and fluids can simultaneously switch between straight or curved and hot and cold by controlling the volume and temperature of tiny fluid-filled pixels. Changing the volume of fluid inside the pixels can change the direction in which the flaps flip (similar to an old-fashioned flip clock), and changing the temperature allows the pixels to communicate via infrared energy.The research results are published in the journal scientific progress.

Taufik’s interest in the interplay of elasticity and capillary forces (or elastic capillary action) began as a graduate student, covered the basic science of hair wetting, and led to his research on soft robotic displays at Illinois.

“An everyday example of elastic capillarity is what happens in our hair when we shower,” Taufik said. “When our hair gets wet, it sticks together and bends or bunches because capillary forces are exerted and released when it dries.”

Video of Single Fin Arrangement

In the lab, the team created tiny boxes, or pixels, a few millimeters in size that contained fins made of a flexible polymer that flexed when the pixels were filled with liquid and drained using a micropump system. Pixels can have single or multiple fins and be arranged in arrays to form a display to convey information, Taufik said.

“We’re not limited to cubic pixel boxes either,” Taufik said. “The fins can be arranged in different directions to create different images, even along curved surfaces. The control is precise enough to enable complex movements, such as simulating a flower blooming.”

Another feature of the new display is the ability to send two signals at the same time — one that can be seen with the human eye and one that can only be seen with an infrared camera, the research report said.

Displays controlled by flexible fins and droplets are more versatile and efficient than LED screens

A schematic of the mechanism showing both the optical and infrared signals for the words “OK” and “NO”. In this graphic, cold pixels are represented by blue and hot pixels by pink. Image credit: Sameh Tawfick.

“Because we can control the temperature of these individual droplets, we can display information that can only be seen with infrared devices, or we can send two different pieces of information at the same time,” Taufik said. , the new monitor has some limitations.

While building the new device, the team discovered that the tiny pumps needed to control the pixel fluids were not commercially available, and that the entire device was gravity-sensitive, meaning it would only work when it was in a horizontal position.

“Once we rotate the display 90 degrees, performance degrades significantly, which is not good for applications like billboards and other public-facing signs,” Tawfick said. “The good news is that we know that when droplets get small enough, they become insensitive to gravity, just like when you see a raindrop sticking to a window it doesn’t fall. We found that if we use With droplets five times smaller, gravity will no longer be an issue.”

Video of Quad Fin Arrangement

The team says that since the science behind gravity’s effect on droplets is well understood, it will provide a focus for their next steps in applying this emerging technology.

Tawfick said he’s excited to see where the technology is headed because it brings new ideas to the huge market space for large reflective displays. “We’ve developed an entirely new type of display that requires minimal energy, is scalable, and is even flexible enough to be placed on curved surfaces.”

More information:
Jonghyun Ha et al., A polymorphic display and texture integration system controlled by capillarity, scientific progress (2023). DOI: 10.1126/sciadv.adh1321. www.science.org/doi/10.1126/sciadv.adh1321

Courtesy of University of Illinois at Urbana-Champaign

citation: Displays Controlled by Flexible Fins and Droplets More Versatile and Efficient Than LED Screens (2023, June 30), Retrieved July 1, 2023 from https://techxplore.com/news/2023-06 -displays-flexible-fins-liquid-droplets.html

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